The present invention is concerned with an apparatus for filling pressure vessels with gases, particularly acetylene gas.
It is known that apparatus for filling pressure vessels with gases basically comprise stationary gas delivery conduits placed in an area which includes positions where the portable cylinders are positioned, alone or in sets, for the cylinder filling operations. These operations require a great deal of time and they also require highly skilled employees when the fluid treated in such apparatus is a dangerous one, due to the specific complexity of said operations.
In fact it is known that the filling of a portable cylinder of dissolved gas is carried out with a mixing operation wherein the gas has to be dissolved into a solvent which is already present in the cylinder. Such an operation needs to cope with the parameters which regulate the mixing and which vary according to the solvent and the solute type. The importance of said parameters requires that the cylinder filling operation be performed by an expert and qualified staff which also is able to correct any anomalous or dangerous situations that may arise.
Due to the length of time the cylinder filling operation needs, it is carried out on many gas-cylinders simultaneously. Each of them is weighed to verify the quantity of solvent it contains, then it is carried to the cylinder filling position where it is coupled by a flexible pipe to the delivery opening of the gas delivery conduit. After the cylinder filling operation has been completed and the gas delivery conduit has been discharged, each gas-cylinder is disconnected from the conduit and carried to a weighing scale to confirm that the amount of bottled gas is within the established limits.
From the foregoing, it can be seen that operations of great skill occur together with simple porterage operations. This increases the operation time, and it creates problems about the management of the staff since, unless unskilled employees are hired to be utilized only during the cylinder carrying operations (a small fraction of the time necessary for the process), the skilled employees are forced to do physically demanding tasks inappropriate to their degree of specialization.
Until now, the possibility of automatic movement of the gas-cylinders has been avoided for this type of apparatus. This possibility is utilized in other types of apparatus for filling pressure vessels, for example in apparatus concerned with liquified petroleum gases. These apparatus do not create particular problems with regard to safety since the pressure value is low and the cylinder filling operation may be carried out over few gas-cylinders automatically, by a continuous control of the weight, to offer a tangible profit in terms of management costs. As far as the apparatus for filling pressure vessels with dissolved gas, the technical problems to solve and the necessity for supervision of the operator have excluded the hypothesis of automatizing the systems.
The problems regarding the management of the staff, time saving and costs that would be achieved by automatization, have led to the present invention, whose main purpose is to provide an apparatus for filling pressure vessels with dissolved gas in which the tasks of carrying the gas-cylinders are eliminated, and the essential high grade of safety is guaranteed.